Supporters of the opposition leader Nikol Pashinyan joined a demonstration in Yerevan, the capital of Armenia, on Wednesday.CreditSergei Grits/Associated Press

MOSCOW — Protesters in Armenia, frustrated by Parliament’s refusal to elect the opposition leader as prime minister, heeded his call for widespread civil disobedience on Wednesday, fanning out across the country to close major squares, roads and schools.

In Yerevan, the capital, demonstrators used vehicles, trash bins and themselves to block streets including the six broad arteries leading to the central Republic Square, as well as the highway to Zvartnots International Airport and the main railroad station.